1. Field of the Invention
The present invention is directed to a vision system which allows inspection of interconnections of optical cards or modules mounted in a rack. More particularly, the present invention is directed to forming such a vision system on a mount which is itself mounted in the rack and which can be used for inspection of fibers in a backplane of the rack while so mounted.
2. Description of Related Art
More and more fiber optics are being used to carry data. To transmit electronic data over an optical fiber, the electronic data is converted into light and sent along the fiber until it reaches its destination where the light is converted back into electronic signals. The optical fiber usually is connected to a fiber in a module or optical card through a bulkhead. The module may be purely optical or electro-optical. The module may perform various functions such as reamplifying the light signals, filtering the light signals, converting the light signals, etc.
Complex systems composed of a plurality of modules are mounted in a rack to facilitate interconnections therebetween. The interconnections are provided by fiber optics in a back plane of the rack. The fiber optics must be inspected and cleaned during, e.g., set up, installation, reconfiguration, and troubleshooting, in order to insure good performance or to determine where a problem in the system is arising. Such an inspection includes determining if there are any defects, such as cracks, scratches, chips, dirt, etc. on the end surface of the optical fiber. Inspection of a fiber optic for defects requires high magnification and high depth perception. A desired magnification for inspection is on the order of approximately 400.times.-800.times.. Optics providing high magnification require bright light.
Recently, inspection of an end of a fiber optic with a bulkhead connected thereto was disclosed in U.S. Pat. No. 5,724,127 to Csipkes et al. entitled "A System and Method for Inspecting an End of a Fiber Optic", the entire contents of which are incorporated by reference. However, the spacing of the cards in the rack, typically on the order of 1 inch or less, prohibits such an inspection system, or any commercially available microscope, from being inserted therebetween. Removal of adjoining modules in the shelves is not an acceptable answer, since such removal would disrupt the testing sequence. Also, there is a risk of damaging the module connectors when removing the modules. The problem is further compounded with the requirement of high magnification. Finally, using an unguided probe microscope presents both magnification/resolution problems as well as risk of optical interface damage due to an unstable linkage to a rigid body.